Dynamical effects in electron tunneling

Abstract

The problem of dynamical screening for electrons tunneling in the metal-insulator-metal system, based on a generalization of the Johnson's nonlocal theory of exchange-correlation potential, is reviewed. The self-energy is evaluated within the GW approximation for electrons coupled to the long-wavelength charge-density oscillations. Potentials are evaluated analytically, and their local limit is examined. The problem is also solved numerically and the results compared with the analytical (nonselconsistent) results. The method is also extended to the case with an external potential on metal electrodes.